Tree testing

Tree testing evaluates a proposed hierarchy by asking participants to find items in a text-only version of it — no visual design, no search. It is sometimes called reverse Card sorting: card sorting generates a structure, tree testing checks one.

How it works

1. Build the tree: the planned menu or table-of-contents hierarchy, as plain text
2. Write tasks: "Where would you look to replace the pump's seal?"
3. Participants click through the tree until they choose an answer
4. Measure the results

What to measure

• Success rate — did participants end at a correct location?
• Directness — did they get there without backtracking?
• Time — how long did it take?
• First click — where did they start? A wrong first click usually predicts failure

Why it works

By removing layout and visual cues, tree testing isolates the structure and its labels — the core of Navigation systems and Labeling systems. Low scores point to categories that don't match users' Mental models or labels that mean different things to different people.

It is one of the most direct ways to measure Findability before anything is built.